1. Field of the Invention
Aspects of the present invention relate to an organic light emitting display device and a driving method thereof, and more specifically, to an organic light emitting display device, and a driving method thereof, capable of improving visibility.
2. Description of the Related Art
Recently, various flat panel display devices having reduced weight and size, which are disadvantages of cathode ray tubes, have been developed. A flat panel display device can be classified as a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), and an organic light emitting display (OLED), etc.
An organic light emitting display device displays an image using an organic light emitting diode (OLED), which generates light by the recombination of electrons and holes (positively charged particles).
The market for such an organic light emitting display device, which has excellent color reproduction and reduced thickness, has been expanded to portable display devices, including PDA, MP3, DSC, and cellular phone devices.
However, since the organic light emitting display device emits light, according to a variation in the amount of current applied thereto, it consumes a large amount of current when emitting bright light. Therefore, in order to apply the organic light emitting display device to various displays, a reduction of the power consumption is sought.
In order to reduce the power consumption of the organic light emitting display device, by lowering only a driving voltage for an image as a whole, the brightness of darker portions of an image is also reduced, such that overall image quality is reduced.
Also, portable display devices, using the organic light emitting display device, are exposed to various environments. Therefore, the visibility of images displayed on the portable display device may be varied, according to the surrounding environment (surrounding luminance, etc). In particular, the visibility of images displayed on the portable display device may be suddenly degraded, when exposed to sunlight that is brighter than the brightness of image.
Therefore, a need exists for the development of an organic light emitting display device that is capable of improving its visibility, according to the surrounding environment.